Field of the Invention
This invention relates to power battery systems, and more particular, to an electrode board having security devices and a power battery system using the electrode board.
Description of the Related Art
As a new type of batteries, lithium iron phosphate batteries have being rapidly developed in recent years. The lithium iron phosphate batteries are widely employed as powers for vehicles such as cars and buses.
In order to provide a desirable output voltage and output current, a power battery system employed in a vehicle usually includes a number of single lithium iron phosphate batteries. Generally, the power battery system can be arranged in two arrangements. In a first arrangement, all of the single batteries of the power battery system can be arranged in a number of parallel groups that are connected in series. Each of the parallel groups includes a number of batteries connected in parallel. In a second arrangement, all of the single batteries of the power battery system can be arranged in a number of series groups that are connected in parallel. Each of series groups includes a number of batteries connected in series.
For the first arrangement of the power battery system, each single battery of each parallel group can be balanced by the other single batteries in the same parallel group and usually is in accordance with the other single batteries in the same parallel group. However, when one single battery of one parallel group occurs short circuit, it is served as a load of the other single batteries in the same parallel group, resulting in the other single batteries in the same parallel group discharging the single battery occurred short circuit, which may bring serious consequence.
For the second arrangement of the power battery system, when one single battery of one series group occurs short circuit, the other series groups discharge power to the single batteries occurred short circuit through return circuits formed between the series groups. When the series group in which the single battery occurred short circuit reaches a rated voltage, the other series group will stop discharging. It is difficult to balance each series group of single batteries with other series groups of single batteries. To balance the each series group of single batteries, a parallel branch circuit can be connected to each series group in parallel. However, this brings other problems, for instance, when one single battery of one series group occurs short circuit, the series group will be shorted circuit by the parallel branch circuit connected to the series group in parallel, the other series groups will quickly discharge the single battery occurred short circuit, the temperature of the single battery occurred short circuit will quickly rise, this may resulting in explosion and insecurity to use the power battery system.
In addition, when an electric bus or an electrical car runs, fiercely vibration usually happens to the power battery system equipped in the electric bus or the electrical car runs. The power battery system arranged in the first arrangement does not have any anti-vibration structure.
It is desirable to provide an invention, which can overcome the problems and limitations mentioned above.